The present invention relates to, in order to protect the global environment, a method of disassembling for scraping a flat panel display constituted by airtightly joining via a frame with frit glass or the like two substrates, i.e., a face plate (front glass substrate) and rear plate (rear glass substrate) mainly containing glass, a method of reusing a flat panel display, separating and recovering lead as a hazardous metal element among metal elements used for the flat panel display, and effectively reusing other noble metal elements and rare-earth elements, a method of dismantling an image forming apparatus welded with frit glass and recycling its face plate and rear plate, a method of recovering and reusing a spacer, a method of recovering fluorescent substances from a flat display apparatus or CRT (Cathode Ray Tube) for emitting light by irradiating a fluorescent substance-coated portion with an electron beam or ultraviolet ray, a display apparatus manufacturing method, an image display apparatus suitable for dismantling, disassembly, and reuse, a residual hazardous metal amount inspection apparatus for inspecting a hazardous metal amount contained in a waste or the like, and a fluorescent substance recovery method and apparatus in a flat display panel.
Conventionally, most of scrapped home appliances are shredded, valuables such as metals are recovered, and the remainders are disposed of as industrial wastes to a xe2x80x9cleast controlled landfill sitexe2x80x9d where the wastes are merely buried in a dug hole.
In recent years, a shortage of the capacity of disposal sites poses a serious problem, and environmental pollution by hazardous substances also poses a serious problem. For example, the cathode ray tube of a television uses a large amount of lead-containing glass. According to trial calculation by the Environment Agency, lead contained in scrapped cathode ray tubes amounts to 20,000 t every year, and most of lead is buried in least controlled landfill sites. However, rainwater naturally permeates in least controlled landfill sites, and these sites are not equipped with any drainage facility. It is being recognized that lead as a hazardous substance may diffuse.
Under these circumstances, conventional processing methods must be reconsidered. As for the cathode ray tube of a television, studies of shredding cathode ray tube glass into cullets (small glass pieces) and reusing them for cathode ray tubes have been made by Association for Electric Home Appliances. Of these studies, a system of extracting a cathode ray tube from a television main body and shredding the cathode ray tube into glass cullets has been developed (see, e.g., xe2x80x9cElectrotechnologyxe2x80x9d, January, 1997).
A method of recovering glass as cullets is disclosed in, e.g., Japanese Laid-Open Patent Application No. 61-50688. There is also known a method of shredding cathode ray tube glass into cullets (small glass pieces) and reusing them for cathode ray tubes (e.g., Japanese Laid-Open Patent Application No. 9-193762). A method of separating a cathode ray tube into a face plate and funnel in accordance with materials, and shredding them into cullets is disclosed in, e.g., Japanese Laid-Open Patent Application No. 05-185064. Further, a method of separating a cathode ray tube into a face plate and funnel, peeling fluorescent substances and a black mask from the face plate, and recycling the face place is disclosed in Japanese Laid-Open Patent Application No. 7-037509.
To reuse cathode ray tube glass, the glass must be separated into panel glass and lead-containing funnel glass. This is because, if lead is mixed in panel glass by a predetermined amount or more, a browning phenomenon occurs, and the lead-containing glass cannot be reused as a raw material of the panel glass. For this reason, a cathode ray tube is separated into a panel and funnel. For this purpose, there are proposed a method of defining a position to cut a cathode ray tube (Japanese Laid-Open Patent Application No. 9-115449), and a method of melting frit glass which joins a panel and funnel, thereby separating the panel and funnel (Japanese Laid-Open Patent Application No. 7-45198).
As a technique of separating a funnel and panel welded with frit glass, a technique of separating a funnel and panel using thermal distortion in heat treatment is known as disclosed in, e.g., Japanese Laid-Open Patent Application Nos. 5-151898, 7-029496, 9-200654, and 9-200657.
In recent years, studies for applying cold cathode elements have enthusiastically been done. Known examples of the cold cathode elements are surface-conduction type electron-emitting elements, field emission type electron-emitting elements, metal/insulator/metal type electron-emitting elements. Compared to a thermionic cathode element, the cold cathode element can emit electrons at a low temperature. The cold cathode element does not require any heater, is simpler in structure than the thermionic cathode element, and can form a small element. Even if many elements are arranged on a substrate at a high density, problems such as thermal melting of the substrate hardly arise. In addition, the response speed of the thermionic cathode element is low because it operates upon heating by a heater, whereas the response speed of the cold cathode element is high.
Of cold cathode elements, surface-conduction type electron-emitting elements have a simple structure, can be easily manufactured, and allow forming many elements in a wide area. As disclosed in Japanese Laid-Open Patent Application No. 64-31332 filed by the present applicant, a method of arranging and driving many elements has been studied.
As applications of surface-conduction type electron-emitting elements, e.g., image forming apparatuses such as an image display apparatus and image recording apparatus, charge beam sources, and the like have been studied.
Particularly as applications to image display apparatuses, as disclosed in U.S. Pat. No. 5,066,883 and Japanese Laid-Open Patent Application Nos. 2-257551 and 4-28137, an image display apparatus using a combination of a surface-conduction type electron-emitting element and a fluorescent substance which is irradiated with an electron beam to emit light has been studied. The image display apparatus using a combination of a surface-conduction type electron-emitting element and fluorescent substance is expected to exhibit more excellent characteristics than other conventional types of image display apparatuses. For example, this image display apparatus is superior to a recent popular liquid crystal display apparatus in that the image display apparatus does not require any backlight because of self-emission type and that the view angle is wide.
A method of driving many field emission type electron-emitting elements arranged side by side is disclosed in, e.g., U.S. Pat. No. 4,904,895. A known application of FE type electron-emitting elements to an image display apparatus is a flat display reported by R. Meyer et al. [R. Meyer: Recent Development on Micro-tips Display at LETIxe2x80x9d, Tech. Digest of 4th Int. Vacuum Micro-electronics Conf., Nagahama, pp. 6-9 (1991)].
An application of many metal/insulator/metal type electron-emitting elements arranged side by side to an image display apparatus is disclosed in Japanese Laid-Open Patent Application No. 3-55738.
Of these image forming apparatuses using electron-emitting elements, a thin flat display is space-saving and lightweight, and receives a great deal of attention as a substitute for a cathode ray tube type image display apparatus.
The interior of the airtight container in the image forming apparatus is kept at a vacuum of about 10xe2x88x926 Torr. As the display area of the image display apparatus increases, the airtight container requires a means for preventing a rear plate and face plate from being deformed or destructed by the difference between internal and external pressures of the airtight container. If the rear plate and face plate are made thick, this increases the weight of the image display apparatus, and generates distortion and disparity of an image when viewed diagonally. Thus, the airtight container generally employs spacers each of which is made of a relatively thin glass plate whose surface is covered with an antistatic conductive film.
Flat displays including a vacuum fluorescent display (VFD), plasma display (PDP), and surface-conduction type electron source display (SED) in addition to the field-emission type electron source display (FED) and MIM type display described above are space-saving and lightweight, and receive a great deal of attention as substitutes for cathode ray tube type display apparatuses. Many flat displays have been studied and developed.
For example, the present applicant offers several proposals for an electron source constituted by arraying on a substrate many surface-conduction type electron-emitting elements as one type of cold cathode type electron-emitting elements, and an image display apparatus using this electron source.
The structure of the surface-conduction type electron-emitting element, the structure of the image display apparatus using this, and the like are disclosed in detail in, e.g., Japanese Laid-Open Patent Application No. 7-235255, and will be described briefly.
FIGS. 68A and 68B show a structure of a surface-conduction type electron-emitting element. Reference numeral 411 denotes a substrate; 412 and 413, a pair of element electrodes; and 414, a conductive film which partially has an electron-emitting portion 415. The substrate 411, element electrodes 412 and 413, conductive film 414, and electron-emitting portion 415 constitute an electron-emitting element 416.
As a method of forming the electron-emitting portion 415, a voltage is applied between the pair of element electrodes 412 and 413 to deform, change of properties, or destruct part of the conductive film, thereby increasing the resistance. This is called xe2x80x9celectrification forming processingxe2x80x9d. To form an electron-emitting portion having good electron emission characteristics by this method, the conductive film is preferably made of fine conductive particles. An example of the material is fine PdO particles. The voltage applied in electrification forming processing is preferably a pulse voltage. This processing can adopt either one of a method of applying pulses having a predetermined peak value, as shown in FIG. 69A, and a method of applying pulses whose peak value gradually increases, as shown in FIG. 69B.
To form a fine conductive particle film, fine conductive particles may be directly deposited by gas deposition. Instead, a method of applying the solution of a compound (e.g., organic metal compound) containing the constituent element of the conductive film and annealing the coating into a desired conductive film is desirable because no vacuum device is required, the manufacturing cost is low, and a large electron source can be formed. As a method of applying the organic metal compound solution, a method of applying the solution to only a necessary portion using an ink-jet apparatus is desirable because the method does not require any extra step for patterning of the conductive film.
After the electron-emitting portion is formed, a pulse voltage is applied between the element electrodes in a proper atmosphere containing an organic substance (this will be called xe2x80x9cactivation processingxe2x80x9d). Then, a deposition film mainly containing carbon is formed at the electron-emitting portion and its vicinity to increase a current flowing through the element and improve electron emission characteristics.
After that, a step called xe2x80x9cstabilization processingxe2x80x9d is preferably performed. In this processing, while a vacuum container and electron-emitting element are heated, the vacuum container is kept evacuated to sufficiently remove an organic substance and the like, thereby stabilizing the characteristics of the electron-emitting element.
A method of forming the conductive film of an electron source using a surface-conduction type electron-emitting element by an ink-jet apparatus is disclosed in, e.g., Japanese Laid-Open Patent Application No. 8-273529.
The ink-jet apparatus will be explained briefly. Methods of discharging ink from the ink-jet apparatus are roughly classified into two types. According to the first method, a liquid is discharged as droplets using the contraction pressure of a piezoelectric element disposed at a nozzle. This method is called a piezo-jet method. In this method, a conductive thin film material is stored in an ink reservoir, and a predetermined voltage is applied to an electrical signal input terminal to contract the cylindrical piezoelectric element, thereby discharging a liquid as droplets.
According to the second method, a liquid is heated and bubbled by a heating resistor to discharge droplets. This method is called a bubble-jet method. In a bubble-jet type ink-jet apparatus, the heating resistor generates heat to bubble a liquid, thereby discharging droplets from a nozzle.
By using this ink-jet apparatus, an organic metal compound solution is applied as droplets to only a predetermined position. After the solution is dried, the organic metal compound is thermally decomposed by heating processing to form a conductive film from small particles of a metal or metal oxide.
FIG. 1 shows a structure of an image display apparatus. In FIG. 1, reference numeral 1 denotes a rear plate; 2, a face plate having a fluorescent film 2b, metal back 2c, and the like formed on the inner surface of a substrate 2a; and 3, a support frame. The rear plate 1, support frame 3, and face plate 2 are joined and tightly sealed with frit glass to constitute an image display apparatus 15.
Flat panel displays having this structure are expected to abruptly increase in size and production. In these flat panel displays, frit glass used for sealing contains lead. The fluorescent substance 2b serving as an image forming member, a spacer 4, and the like are high-cost members. Similar to cathode ray tube glass, establishment of a recovery system becomes an important subject in terms of xe2x80x9cnon-hazardous processingxe2x80x9d, xe2x80x9cvolume reductionxe2x80x9d, and xe2x80x9crecyclingxe2x80x9d.
Problems to be solved by the present invention will be described in the following order, and examples for respective solving means and embodiments will be explained in this order.
[Problem 1] The FPD has a different structure from that of a cathode ray tube, and requires another processing method. That is, the FPD is constituted by airtightly joining two substrates, i.e., a face plate and rear plate mainly containing glass via a frame with frit glass. In general, frit glass containing a large amount of lead component so as to enable low-temperature baking is used.
For the same reason as a cathode ray tube, the FPD must be separated into glass not containing any lead and glass containing lead in order to reuse glass. In reusing members other than glass, lead must be removed.
The present invention has been made to solve the above problem, and has as its object to provide a processing method of easily reusing a scrapped FPD.
[Problem 2] It is another object of the present invention to provide a disassembly processing method including a separation/recovery method for lead as a hazardous metal, and a recovery/reuse method for rare elements such as noble metal elements and rare-earth elements.
[Problem 3] When a flat display is scrapped owing to generation of defects during the manufacture or upon the lapse of a service life, the entire display is shredded and scrapped, which increases the scrap amount. Recently, social demands arise for minimizing generation of wastes along with industrial activities, and reuse of members is becoming an imminent subject.
When a constituent material contains a hazardous element or the like, the hazardous element must be separated. A rear plate having electron-emitting elements that determines the performance of an image display apparatus often uses a high-cost substrate in order to obtain uniform element characteristics. Particularly, an element electrode which is first formed on a rear plate substrate is often made of a strong material which can resist subsequent steps.
The present invention has been made to solve this problem, and has as its object to provide a disassembly method of easily reusing a rear plate as an important constituent component of a scrapped image display apparatus, to provide a separation/recovery method for an element such as lead contained in a constituent material, and to efficiently form conductive films including the electron-emitting portions of a plurality of electron-emitting elements to be formed.
[Problem 4] When a flat display is scrapped owing to generation of defects during the manufacture or upon the lapse of a service life, the entire display is shredded and scrapped, which is economically undesirable because the constituent material contains a relatively high-cost material. Especially, the panel uses many spacers, and the manufacture of spacers requires a high manufacturing cost and long time because glass must be formed into thin pieces and conductive films must be formed. Even when a display is scrapped due to any reason, the cause is rarely a defective spacer, and spacers can often be reused without any problem.
For this reason, in scraping a flat display, spacers are desirably separated from other members, recovered, and reused.
As described above, the spacer is a thin plate and formed from a glass substrate, and may be damaged while a display is dismantled. Thus, development of a method capable of recovering spacers without any damage is desired.
[Problem 5] Conventionally, rare-earth elements have hardly been recovered from a display apparatus scrapped after use.
This is because (1) the amount of rare-earth elements used per display apparatus is very small, and the recovery is difficult, (2) rare-earth elements are used not as single substances but as compounds or alloys, and the separation cost is high, and (3) relatively low-cost imported rare-earth elements can be acquired at lower cost under the influence of the strong yen.
However, the recycling of these materials is desirably promoted in terms of environmental conservation and stably supply of rare-earth element resources. A method of recovering rare-earth elements from industrial products is an important subject. Note that rare-earth elements are mainly contained in fluorescent substances.
Fluorescent substances also contain chromium and sulfur elements, and these elements are also desirably recovered in terms of environmental conservation.
On the other hand, a face plate from which fluorescent substances are recovered loses almost all the smoothness of the inner surface. For this reason, such a face plate is conventionally shredded into cullets, buried in a least controlled landfill site, or reused as a glass material. In recent years, there are proposed a method of renewing the smoothness of the inner surface again by acid treatment and reusing the face plate, instead of shredding the face plate into cullets. However, this method is no longer effective because least controlled landfill sites are being saturated. Moreover, acid treatment is wet treatment, and is not preferable in terms of the cost and work environment.
The present invention has been made in consideration of the above situation, and has as its object to provide a method of efficiently recovering fluorescent substances contained in a display apparatus, and recovering and reusing a face plate while maintaining or renewing the smoothness of the inner surface.
[Problem 6] To dismantle, disassemble, and reuse an image display apparatus having an airtight container kept at a pressure lower than the atmospheric pressure, the interior of the airtight container must be returned to the atmospheric pressure. In returning to the atmospheric pressure, as the pressure difference from the internal pressure of the airtight container is larger, a larger amount of gas such as air often abruptly flows into the airtight container to damage the interior of the airtight container or destruct the airtight container. This may unexpectedly destruct the airtight container to scatter fragments, which is not preferable in terms of safety. This does not pose a serious problem when a CRT is shredded into cullets and reused as a glass material. However, to maximally reuse each member of an image display apparatus, the destruction not only increases wastes such as garbage in terms of resource conservation, but also wastes energy and labor. Particularly in an FPD, the container incorporates many atmospheric pressure-resistant constituent members such as spacers. The destruction greatly damages the atmospheric pressure-resistant constituent members, and the destructed members damage and destruct the interior of the airtight container of the image display apparatus to inhibit reuse of these members. A spacer requires a higher cost than other members because the shape of the side surface is made uniform or the spacer is uniformly coated with a film having a conductivity corresponding to the specifications of an image display apparatus in order to prevent distortion of an image.
The present invention has been made to solve the above problem, and has as its object to reuse a member in dismantling and disassembly by smoothly returning the interior of an evacuated airtight container of an image display apparatus to an external pressure.
[Problem 7] When a flat display is scrapped owing to generation of defects during the manufacture or upon the lapse of a service life, the entire display is shredded and scrapped, which poses an environmental problem, and is not economically preferable because the constituent material of an element includes a relatively high-cost material. For example, a panel uses many spacers. The spacers require a high manufacturing cost and long time because glass must be shredded into thin pieces and conductive films must be formed. Further, a rear plate, face plate, and support frame can be reused after portions which need to be repaired in accordance with the situation are appropriately processed.
For this reason, demands arise for recovering and reusing members without any damage and efficiently recovering resources in disassembling a flat display due to generation of defects during the manufacture or upon the lapse of a service life.
It is still another object of the present invention to provide a method of safely, easily dismantling a flat display into constituent members, and a flat display panel suitable for this disassembly.
[Problem 8] In disassembling and fractionating a cathode ray tube, flat panel display, and the like, the hazardous metal amount must be quantitatively detected for wastes left after fractionated members for reuse are recovered, and whether the residual amount is an allowance or less must be checked and confirmed to prevent environmental pollution/destruction. As for fractionated members for reuse, the residual amount of lead (hazardous metal) is wanted to be quantitatively detected for fractionation depending on the presence/absence of lead.
To detect lead in a member, an inspection method using a fluorescent X-ray or the like is known. This method, however, must scan the entire surface of a member to be inspected, and becomes cumbersome for many targets to be inspected such as glass cullets. Inspection target objects are limited, quantitative detection is impossible, and the method is difficult to apply.
The present invention has been made to solve the conventional problem, and has as its object to provide a residual hazardous metal amount inspection apparatus capable of quantitatively detecting the amount of hazardous metal such as lead left in an inspection target object such as a fractionated glass member or waste, inspecting various members without particularly limiting inspection target objects, and easily quantitatively detecting the hazardous metal amount without any cumbersome operation in disassembling and fractionating a flat display panel or the like.
[Problem 9] A technique of disassembly processing for recycling a flat display panel is being developed, and conventional related arts cannot be directly adopted. For example, if the technique of cathode ray tube glass disassembly processing disclosed in Japanese Laid-Open Patent Application No. 9-193762 or the like is employed, the weight of a rear plate or face plate is applied to a spacer 4 to destruct it in separating the spacer 4. This technique cannot be applied to disassembly of a flat display panel.
The present invention has been made to solve the conventional problem, and has as its object to provide a flat panel display disassembly apparatus capable of performing disassembly processing by proper steps, recovering a directly reusable constituent member such as a spacer without any damage, and preferably recycling the recovered member.
[Problem 10] An FPD has a different structure from that of a cathode ray tube, and requires another processing method. The FPD is constituted by airtightly joining two substrates, i.e., a face plate and rear plate mainly containing glass via a frame with frit glass. In general, frit glass containing a large amount of lead component so as to enable low-temperature baking is used. In some cases, the material of a wiring line and the constituent material of a face plate contain lead in addition to frit glass. For the same reason as a cathode ray tube, the FPD must be separated into glass not containing any lead and glass containing lead in order to reuse glass. Also in reusing members other than glass, lead must be removed.
To remove lead, a method of selectively dissolving and separating a lead component using an aqueous acid or alkaline solution is effective. However, practicing this method on a large scale requires a large amount of aqueous solution for dissolving lead and a large amount of water for the subsequent cleaning step. To heat and flow a solution, large energy must be applied. This increases the processing cost.
The present invention has been made to solve the above problem, and has as its object to provide a method of processing a scrapped FPD at low cost.
[Problem 11] Rare-earth elements have hardly been recovered from a display scrapped after use. This is because (1) the amount of rare-earth elements used per display is very small, and the recovery is difficult and has not been automated, (2) rare-earth elements are used not as single substances but as compounds or alloys, and the separation cost is high, and (3) relatively low-cost imported rare-earth elements can be acquired at lower cost under the influence of the strong yen.
However, the recycling of these materials must be promoted in terms of environmental conservation and stable supply of rare-earth element resources. A method of recovering rare-earth elements from industrial products is becoming an important subject. Some home appliance manufacturers start recovery business for CRTs, whereas demands arise for immediately promoting the recycling of flat panel displays.
The present invention has been made in consideration of the above situation, and has as its object to provide a fluorescent substance recovery method and apparatus capable of efficiently, easily dismantling a flat display panel, and effectively recovering particularly fluorescent substances.
[Problem 12] An FPD (Flat Panel Display) has a different structure from that of a cathode ray tube, and requires another processing method. The FPD is constituted by airtightly joining two substrates, i.e., a face plate 2 and rear plate 1 mainly containing glass via a frame with frit glass. In general, frit glass containing a large amount of lead component so as to enable low-temperature baking is used. In some cases, the material of a wiring line and the constituent material of a face plate contain lead in addition to frit glass. For the same reason as a cathode ray tube, the FPD must be separated into glass not containing any lead and glass containing lead in order to reuse glass. In reusing members other than glass, lead must be removed.
To remove lead, a method (submergence processing) of selectively dissolving and separating a lead component using an aqueous acid or alkaline solution is effective. However, practicing this method on a large scale requires a large amount of aqueous solution for dissolving lead and a large amount of water for the subsequent cleaning step must be prepared. Further, to heat and flow a solution, large energy must be applied. To suppress the cost and complete processing within a short time, many glass plates obtained by disassembling a scrapped FPD must be processed by putting them into a submergence processing bath at once. In addition, quickly conveying glass plates between processing baths requires a convey mechanism for conveying many glass plates at once.
The present invention has been made in consideration of the above situation, and has as its object to provide a substrate processing method and apparatus of realizing efficient and appropriate submergence processing.
[Problem 13] In reusing substrate glass, a rear plate 1 and face plate 2 are separated from other members. Wiring lines, elements, and the like formed on the substrate are removed to obtain a single glass member. The glass member can be reused as a substrate, or can be shredded into cullets and newly reused as a glass substrate or the material of another product.
When, however, wiring lines, electron-emitting elements, frit glass, and the like are formed on a glass substrate, and soda-lime glass is used as the substrate, a thin film may be formed on the surface in advance. Some of the materials may be in tight contact with the glass substrate, or some of the elements may gradually diffuse into the glass substrate. Thus, the thin film may be difficult to completely separate from substrate glass.
In shredding used glass into cullets and reusing them, if an element other than a constituent element is mixed in glass cullets, the mixed element influences the physical properties and color glass. Impurity element-containing glass may not be reused. Even when glass is reused as a substrate, the glass is desirably restored to an initial glass substrate state as much as possible.
The present invention has been made in consideration of the above situation, and has as its object to provide a glass substrate processing method of realizing effective and efficient reuse of substrate glass.
Means for solving the problems of the present invention will be explained in an order corresponding to the problems to be solved by the above-described inventions.
[Solving Means 1] To achieve the above object, according to the present invention, a disassembly processing method for an FPD having a structure in which two substrates, i.e., face plate and rear plate mainly containing glass are airtightly joined via a frame with frit glass is characterized by separating a portion of the frame joined with frit glass from remaining portions.
According to the present invention, a disassembly processing method for an FPD which incorporates a spacer and has a fluorescent screen on the inner surface of a face plate is characterized by comprising leaving the spacer and the fluorescent screen at remaining portions in separating a portion of the frame joined with frit glass.
The present invention is characterized by cutting part of the face plate and the rear plate to separate a portion of the frame joined with frit glass from remaining portions.
In the present invention, means for determining a cutting position includes means (video camera) for detecting a position of the frame joined with frit glass.
[Solving Means 2] To achieve the above object, according to the present invention, an FPD having a structure in which two substrates, i.e., face plate and rear plate mainly containing glass are airtightly joined via a frame with frit glass is characterized by comprising dissolving a joint portion with nitric acid to peel the face plate and the rear plate. In the present invention, the FPD may incorporate a spacer joined with frit glass.
As a method of dissolving frit glass with nitric acid, a method of dipping a joint portion in nitric acid is safe and easy because nitric acid must penetrate deep into the frit joint portion. The present invention adopts this method, but a method of, e.g., spraying nitric acid from a nozzle to joint portions is also available.
The frit joint portion to be dissolved with nitric acid can employ (1) a method of dipping all joint portions in nitric acid to dissolve and peel them, and separating, scraping, and reusing respective portions, and (2) a method of leaving a portion to be reused without eroding it with an acid, dipping remaining portions in nitric acid to dissolve, peel, and scrap them. Either method can separate only a hazardous lead component among metal components dissolved with nitric acid, and can reuse and recycle the remaining elements.
[Solving Means 3] To achieve the above object, according to the present invention, a rear plate recycling method comprises the step of dipping a welded portion in a nitric acid solution to dissolve frit glass, and the step of forming a conductive film by an ink-jet method, in scraping an image display apparatus constituted by at least a rear plate having a plurality of electron-emitting elements each formed from a pair of element electrodes and a conductive film, a face plate having an image forming member on which an image is formed upon collision of electrons emitted by the electron-emitting elements, and a support frame which connects the rear plate and face plate and maintains the internal pressure, the rear plate, face plate, and support frame being welded with frit glass.
According to the present invention, the rear plate is dismantled by chemically dissolving frit glass without mechanical cutting or the like. Thus, the rear plate can be recovered and reused without damaging the rear plate substrate and element electrode. Wastes can be decreased, resources can be effectively used, and the cost can be reduced. Elements such as Pb are eluted in a dipping nitric acid solution, so that they can be easily recovered. In recycling the rear plate, a conductive film is formed by an ink-jet method. Since the conductive film formation material is used for only a necessary portion, the amount of conductive film material can be minimized. Even when a defect is found after the conductive film is formed, only the defective portion can be formed again.
[Solving Means 4] The present invention has been made in consideration of the above situation. According to the present invention, there is provided a spacer recovery method in a flat display which has at least a rear plate with a plurality of electron-emitting elements, a face plate that is arranged to face the rear plate and has an image display portion, a frame, and spacers for holding an interval between the rear plate and the face plate against an atmospheric pressure, the rear plate, the face plate, the frame, and the spacers being welded with frit glass, characterized in that a spacer recovery jig for avoiding contact between the spacers or between the spacers and a peripheral member is used in dipping welded portions between the spacers and the rear plate or the face plate in a nitric acid solution to dissolve frit glass.
The spacer recovery jig used in an aspect of the present invention includes a flat plate having one or a plurality of recesses capable of storing the spacers. The spacer recovery jig in another aspect includes a jig having distal ends capable of pinching and holding the respective spacers, and an arm capable of moving the distal ends in an arbitrary direction.
According to the present invention, since spacers can be recovered with almost no damage in dismantling a flat display, they can be easily reused, resources can be effectively used, and the cost can be reduced. In addition, since the recovery step does not require any fine manual work, spacers can be safely recovered.
[Solving Means 5] According to the present invention, a method of recovering fluorescent substances from a display apparatus in which fluorescent substances are applied to a substrate, and caused to emit light, thereby obtaining display, characterized in that the fluorescent substances applied to the substrate are recovered by both a brush and a suction unit.
A display apparatus manufacturing method according to the present invention is characterized by reusing for a display apparatus a substrate from which fluorescent substances are removed by the method of recovering fluorescent substances from a display apparatus according to the present invention.
The present invention is effective for recovery of fluorescent substances and a substrate such as a face plate from a display apparatus such as a CRT or flat display apparatus in which fluorescent substances are applied to a substrate such as a face plate, and caused to emit light by irradiation of an electron beam or an ultraviolet ray. A substrate surface coated with fluorescent substances is swept with a brush to brush off fluorescent substances, or fluorescent substances and a black matrix component. When the smoothness of the substrate surface is held or impaired, the substrate is reformed, and the fluorescent substances and black matrix component are swept and sucked by a suction device. The fluorescent substances and black matrix are further transferred to the fluorescent substances separation process. The substrate such as a face plate is unloaded from the step while the smoothness of the surface is held or kept unimpaired, and then the substrate is directly reused as a substrate such as a face plate.
As a flat display apparatus for performing display by causing fluorescent substances to emit light, a type of apparatus for irradiating fluorescent substances with an electron beam includes a display apparatus using an electron-emitting element (to be described later) and a vacuum fluorescent display tube for emitting light by a low-speed electron beam. A type of apparatus using an ultraviolet ray includes a plasma display apparatus. When fluorescent substances are irradiated from a back surface with an electron beam or ultraviolet ray, and emit visible light from a front surface, the fluorescent substances are applied to the face plate of the flat display apparatus. When visible light is emitted from a surface on which fluorescent substances are irradiated with a low-speed electron beam, like a vacuum fluorescent tube, the fluorescent substances are applied to the rear plate.
[Solving Means 6] According to the present invention, in order to achieve the above object, an image display apparatus is characterized by comprising display means for displaying an image, an airtight container, and means for gradually changing an interior of the airtight container close to a pressure outside the airtight container as needed.
The present invention is characterized in that the image display apparatus further comprises an exhaust device, and the means for changing the interior of the airtight container close to the pressure outside the airtight container is arranged at a different position on the airtight container from means connected to the exhaust device. The means for changing the interior of the airtight container close to the pressure outside the airtight container is characterized by comprising a necessary filter.
The present invention is characterized by comprising display means for displaying an image, an airtight container for maintaining an external pressure, an atmospheric pressure-resistant structure member in the airtight container, means connected to an exhaust device for evacuating an interior of the airtight container, and means for gradually changing the interior of the airtight container close to a pressure outside the airtight container as needed.
Since the image display apparatus having this arrangement has the means for gradually changing the interior of the airtight container close to the atmospheric pressure, the internal member of the airtight container is almost free from any stress caused by a change in pressure in dismantling and disassembly.
Thus, the member is hardly destructed, and secondary damage by pieces of the destructed member can be prevented.
[Solving Means 7] According to the present invention, a flat display having at least a rear plate with a plurality of electron-emitting elements, a face plate which is arranged to face the rear plate and has an image display portion, a support frame, and a spacer for holding an interval between the rear plate and the face plate against an atmospheric pressure, the rear plate, the face plate, the support frame, and the spacer being welded with frit glass is characterized in that joining of the rear plate and the support frame. and joining of the face plate and the support frame use frit glasses having different softening temperatures, and joining of the spacer and the substrate uses a frit glass having a softening temperature not less than a higher softening temperature of the frit glass among the two types of frit glasses.
Each of the plurality of frit glasses is characterized to have a softening temperature different by at least 20xc2x0 C. from the softening temperatures of the remaining frit glasses.
The spacer in the present invention is characterized to be joined to either one of the rear plate and the face plate.
A flat display disassembly method according to the present invention is characterized by comprising heating the flat display panel to not less than a softening temperature of a frit glass having the lowest softening temperature, and to not more than the softening temperatures of the remaining frit glasses, melting only the frit glass having the lowest softening temperature to selectively separate only a joint portion joined with the frit glass, and repeating the same procedures to sequentially separate the flat display panel from a joint portion using a frit glass having a lower softening temperature.
A method of separating a joint portion joined with the frit glass having the highest softening temperature may include a method of heating the frit glass to not less than the softening temperature to melt the frit glass, thereby separating the joint portion, or may include a method of dissolving the frit glass with a proper solvent to separate the joint portion.
A flat display having an airtight container storing at least a substrate with a plurality of electron-emitting elements, and a substrate which is arranged to face the substrate and has an image display portion may be characterized in that joint portions between the substrates and the airtight container are joined with frit glasses having different softening temperatures corresponding to a disassembly order.
A flat display having as constituent members at least a rear plate with a plurality of electron-emitting elements, a face plate which is arranged to face the rear plate and has an image display portion, and a support frame for supporting the substrates, the constituent members being welded with frit glass, may be characterized in that joining of the rear plate and the support frame, and joining of the face plate and the support frame use frit glasses having different softening temperatures.
A flat display having an envelope storing an electron-emitting element may be characterized in that a joint portion between a rear plate and a support frame constituting the envelope, and a joint portion between a face plate and the support frame use two types of frit glasses having different softening temperatures, and a joint portion between a spacer for supporting an interval between the substrates and at least one of the substrates is joined using a frit glass having a softening temperature higher than the softening temperatures of the two types of frit glasses or equal to the softening temperature of either type of frit glass.
A flat display disassembly method is characterized by comprising, in disassembling the flat display, heating the flat display stepwise, and sequentially melting and separating the flat display from a joint portion using frit gas having a lower frit gas, thereby disassembling the flat display.
In the flat display according to the present invention, members forming an envelope can be sequentially separated, so that the members can be recovered by a safe and simple method without damaging the envelope and the internal members during the disassembly process. The members can, therefore, be recovered as reusable ones, resources can be effectively used, and the cost can be reduced.
[Solving Means 8] To achieve the above object, a residual hazardous metal amount inspection apparatus for inspecting an amount of hazardous metal such as lead contained in an inspection target object such as a member or a waste disassembled and fractionated for recycling comprises first elution means having, in a bath for dipping the inspection target object, an acid solution for eluting a hazardous metal contained in the inspection target object; cleaning means for cleaning the inspection target object after elution by the first elution means; second elution means having an acid solution for eluting a hazardous metal left on the inspection target object, in a bath for dipping the inspection target object cleaned by the cleaning means; and quantitative detection means for quantitatively detecting a hazardous metal amount eluted in the acid solution of the second elution means.
In the residual hazardous metal amount inspection apparatus of the present invention, an inspection target object is dipped in the bath of the first elution means to elute a hazardous metal contained in the inspection target object with an acid solution in the bath. The inspection target object is transferred to the cleaning means where the object is dipped in the bath of the second elusion means to elute a hazardous metal left on the inspection target object with an acid solution in the bath. This elution solution is supplied to the quantitative detection means, which quantitatively detects a hazardous metal amount contained in the elusion solution.
Hence, in disassembling and fractionating a flat panel display or the like, the amount of hazardous metal such as lead left on an inspection target object such as a fractionated glass member or waste can be quantitatively detected.
[Solving Means 9] According to the present invention, a flat panel display disassembly apparatus for disassembling and recycling a flat panel display in which a frame member is interposed between a rear plate and a face plate to constitute a flat vacuum container, and a spacer for holding a gap between the plates against an atmospheric pressure is fixed to both or either one of the plates comprises first support means for applying a pull-up force to a plate fixed to the spacer to support the plate in order to perform the step of separating the frame member from the vacuum container, second support means for receiving and supporting an edge of the plate fixed to the spacer after the frame member is separated, and spacer recovery means for performing the step of separating the spacer from the plate received and supported by the second support member.
The flat panel display disassembly apparatus according to the present invention further comprises convey means for, after the step of separating the frame member from the vacuum vessel, receiving the supported plate from the first support means, receiving and supporting an edge of the plate, and conveying the plate to the second support means.
In the flat panel display disassembly apparatus according to the present invention, the convey means has a structure which prevents a load of the plate fixed to the spacer from being applied to the spacer.
In the flat panel display disassembly apparatus of the present invention having this arrangement, the first support means supports a plate fixed to spacers by applying a pull-up force in the step of separating a frame member from a vacuum container. The spacers are suspended and are free from the weight of the fixed plate, and the frame member can be separated without applying any load to the spacers.
After the frame is separated, the second support means receives and supports the edge of the plate fixed to the spacers. At this time, the spacers are suspended and are free from the weight of the fixed plate. The step of separating the spacers from the plate received and supported by the second support means is executed by the spacer recovery means while the plate is kept received and supported. Also in the spacer separation/recovery step, the spacers are free from any extra weight, and can be prevented from being damaged.
[Solving Means 10] According to the present invention, a flat panel display disassembly processing method for a flat panel display having a structure in which two substrates, i.e., face plate and rear plate mainly containing glass are airtightly joined via a frame with lead-containing frit glass is characterized by comprising the step of separating and extracting a portion including the face plate and a portion including the rear plate from the flat panel display to be scrapped, and the step of separately collecting pluralities of extracted portions including face plates and extracted portions including rear plates, separately charging the portions in processing baths at once, and executing submergence processing.
The present invention further includes, as characteristic features, that
xe2x80x9cthe submergence processing includes processing using an aqueous acid or alkaline solution;xe2x80x9d
xe2x80x9cthe submergence processing includes processing using an aqueous acid or alkaline solution, and subsequent cleaning processing using water or an organic solvent;xe2x80x9d
xe2x80x9cthe submergence processing is performed by flowing a processing solution in the processing bath;xe2x80x9d
xe2x80x9cthe submergence processing is performed by circulating a processing solution between the processing bath and an outside;xe2x80x9d
xe2x80x9cthe submergence processing is performed by heating a processing solution;xe2x80x9d and
xe2x80x9cthe submergence processing is performed by propagating a vibration or an acoustic wave to an object to be processed.xe2x80x9d
[Solving Means 11] According to the present invention, a flat panel body constituted by joining a pair of panels facing each other via a frame comprises a fixing jig disposed to be retractable with respect to the flat panel body so as to surround the flat panel body placed on a base, wherein the fixing jig swings and comes into contact with the flat panel body from around the flat panel body, thereby fixing the flat panel body.
The flat panel body fixing apparatus according to the present invention is characterized in that the apparatus further comprises a driving mechanism for moving back and forth the fixing jig with respect to the flat panel body, position detection means for detecting a position of the fixing jig on the basis of a moving amount of the fixing jig, and a controller capable of controlling the driving mechanism, and a size of the flat panel body is detected from positional information of the fixing jig obtained by the position detection means.
The flat panel body fixing apparatus according to the present invention is characterized by further comprising chuck means for chucking and fixing the flat panel body via a chucking hole formed in the base.
According to the present invention, a flat panel display fluorescent substance recovery apparatus for recovering fluorescent substances in a flat panel display which includes a face plate, a rear plate, and a frame, and emits light by irradiating the fluorescent substances applied to the face plate with electrons is characterized by comprising the above-described fixing apparatus, the face plate being fixed by the fixing jig from four directions.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that the apparatus comprises a plurality of processing means for recovering the fluorescent substances from the face plate fixed by the fixing apparatus, and the processing means are driven by the controller on the basis of the positional information obtained by the position detection means.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that the processing means include cutting means for separating the face plate and the rear plate, and recovery means for sweeping and sucking the fluorescent substances of the face plate.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that processing work operations by a cutter of the cutting means and a recovery brush of the recovery means are controlled by the controller so as to be performed within predetermined work ranges.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that the apparatus further comprises fluorescent substance detection means for detecting an amount of fluorescent substances left on the face plate, and actuation of the recovery means is controlled based on fluorescent substance amount information obtained by the fluorescent substance detection means.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that the fluorescent substance amount information is defined by a transmittance or an absorbance of visible light transmitting through the face plate.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that the fluorescent substance amount information is defined by a fluorescent intensity generated by irradiating an inner surface of the face plate with an ultraviolet ray or visible light.
The flat panel display fluorescent substance recovery apparatus according to the present invention is characterized in that the fluorescent substance detection means moves following the work range of the recovery brush of the recovery means.
According to the present invention, a flat panel display fluorescent substance recovery method of recovering fluorescent substances in a flat panel display which includes a face plate, a rear plate, and a frame, and emits light by irradiating the fluorescent substances applied to the face plate with electrons is characterized by comprising the step of swinging a fixing jig and fixing the flat panel display from four directions of the flat panel display placed on a base, the step of separating the face plate and the rear plate of the fixed flat panel display, and the recovery step of sweeping and sucking the fluorescent substances of the face plate.
The flat panel display fluorescent substance recovery method according to the present invention is characterized by further comprising the step of detecting a position of the fixing jig on the basis of a moving amount of the fixing jig for fixing the flat panel display.
The flat panel display fluorescent substance recovery method according to the present invention is characterized by further comprising the step of chucking and fixing the flat panel display via a chucking hole formed in a base.
The flat panel display fluorescent substance recovery method according to the present invention is characterized in that cutting work by a cutter is controlled to match a size of the face plate on the basis of positional information of the fixing jig in separating the face plate and the rear plate.
The flat panel display fluorescent substance recovery method according to the present invention is characterized in that recovery work by a recovery brush is controlled to match a size of the face plate on the basis of positional information of the fixing jig in recovering the fluorescent substances of the face plate.
The flat panel display fluorescent substance recovery method according to the present invention is characterized in that the method further comprises the step of detecting an amount of fluorescent substances left on the face plate, and the work of the recovery brush is controlled based on detected fluorescent substance amount information.
The flat panel display fluorescent substance recovery method according to the present invention is characterized by further comprising the step of controlling the recovery brush so as to move following a work range of the recovery brush.
According to the present invention, a flat panel display placed on the base is fixed by the fixing jig by swinging the fixing jib from the four directions of the fluorescent display. At this time, the position of the fixing jig is detected based on the moving amount of the fixing jig, and this positional information is effectively used for the subsequent processing step. That is, in driving a cutter for separating a face plate and rear plate, and a recovery brush for sweeping and sucking the fluorescent substances of the face plate, the work ranges of the cutter and recovery brush are controlled using positional information of the fixing jig.
As a result, the fluorescent substances of the face plate can be efficiently, reliably recovered. The fixing jig can effectively cope with a change in the panel size of the flat panel display, and is very practical.
[Solving Means 12] According to the present invention, a substrate processing method of disassembling a substance mainly constituted by a pair of glass substrates airtightly joined via a frame is characterized by comprising the step of separating the pair of joined substrates, the step of holding a plurality of separated substrates in parallel with each other at a predetermined gap, and the step of conveying the plurality of held substrates at once, and performing predetermined processing.
The substrate processing method according to the present invention is characterized in that the substrates are held to cause surfaces of the substrates to stand substantially vertically.
The substrate processing method according to the present invention is characterized in that the substrates are supported by linearly contacting predetermined portions of the substrates.
According to the present invention, a substrate processing apparatus for disassembling a substrate mainly constituted by a pair of glass substrates airtightly joined via a frame is characterized by comprising a plurality of support members disposed in parallel with each other at a predetermined gap, separated substrates being held between the support members so as to stand substantially vertically.
The substrate processing apparatus according to the present invention is characterized in that at least portions of the support members in contact with the substrates are round or arcuated.
According to the present invention, a flat panel display disassembly processing method for a flat panel display having a structure in which a face plate and a rear plate formed from a pair of substrates mainly containing glass are airtightly joined via a frame with lead-containing frit glass is characterized by comprising, in conveying the glass substrates extracted from the flat panel display to be disassembled and performing submergence processing, processing the face plate or the rear plate by any one of the substrate processing methods described above.
The flat panel display disassembly processing method according to the present invention is characterized by comprising using the above substrate processing apparatus.
The present invention comprises the means for holding glass plates in order to convey at once many glass plates obtained by disassembling scrapped FPDs and perform submergence processing. Since many substrates are preferably held at once, the present invention can realize a method of processing scrapped FPDs at low cost.
[Solving Means 13] According to the present invention, a glass substrate processing method of detecting a surface state of a glass substrate and processing a substrate surface in accordance with a detection result is characterized by comprising the detection step of irradiating the glass substrate surface with a primary X-ray, and detecting a generated fluorescent X-ray to detect an element present on the glass substrate surface, and the removal step of removing an element other than a glass constituent element from the glass substrate surface in accordance with a detection result of the detection step.
The glass substrate processing method according to the present invention is characterized in that the detection step of detecting an element present on the glass substrate surface comprises changing relative positions of the glass substrate and a fluorescent X-ray detector in accordance with a size of the glass substrate.
The glass substrate processing method according to the present invention is characterized in that a fluorescent X-ray detector irradiates with the primary X-ray a region wider than a region in which a fluorescent X-ray can be detected.
The glass substrate processing method according to the present invention is characterized in that an incident angle when the primary X-ray is incident on the glass substrate is not more than a critical angle of the primary X-ray. In addition, the glass substrate processing method according to the present invention is characterized in that the removal step for the glass substrate surface is performed by polishing the glass substrate surface.
The glass substrate processing method according to the present invention is characterized in that the detection step and the removal step for the glass substrate surface are repetitively performed.
According to the present invention, a glass substrate recycling processing method in a flat display including a rear plate having a plurality of electron-emitting elements formed on a glass substrate, a face plate having an image display portion formed on a glass substrate, and a support frame which joins the plates so as to face each other is characterized by comprising applying the above processing method to a substrate surface of the rear plate or the face plate after the rear plate and the face plate are separated and extracted.
The glass substrate recycling processing method in a flat display according to the present invention is characterized in that a wiring line mainly containing Ag is formed on the glass substrate of the rear plate.
The glass substrate recycling processing method in a flat display according to the present invention is characterized in that a thin film containing an element other than a glass constituent element is formed on the glass substrate surface constituting the rear plate.
The glass substrate recycling processing method according to the present invention is characterized in that frit glass for joining the rear plate, the face plate, and the frame is melted to separate the rear plate, the face plate, and the frame.
According to the present invention, a glass substrate recycling processing apparatus in a flat display including a rear plate having a plurality of electron-emitting elements formed on a glass substrate, a face plate having an image display portion formed on a glass substrate, and a support frame which joins the plates so as to face each other is characterized by comprising a mechanism of irradiating with an X-ray a surface of the glass substrate constituting the separated/extracted rear plate or face plate, and detecting a generated fluorescent X-ray to detect an element present on the glass substrate surface, and a mechanism of removing an element other than a glass constituent element from the glass substrate surface.
According to the present invention, residues on a glass substrate surface can be detected by a simple method, and all the elements other than a glass constituent element can be removed in the step of processing used substrate glass. Consequently, glass can be efficiently reused without any wastes.